The present disclosure relates to an image forming apparatus that forms an image by the electrophotography.
In a typical image forming apparatus, such as a printer, that forms an image by the electrophotography, after a toner image is transferred from a photoconductor drum, the electricity is removed from the photoconductor drum by the electricity removing light that is irradiated from a light source of an electricity removing device. Meanwhile, to increase the print speed of the image forming apparatus, it is necessary to increase the linear speed of the drum. This shortens the time period from the time of removal of electricity by the electricity removing device to the time of charging of electricity by the charging device. In particular, since miniaturization of a housing is also demanded for the image forming apparatus, the space inside the housing in which the components are arranged is limited, and it is difficult to arbitrarily select the location for disposing the electricity removing device. As a result, the electricity removing device is normally disposed between the cleaning device and the charging device. In this configuration, the time period from the time of removal of electricity to the time of charging of electricity is very short. Accordingly, the electricity is removed insufficiently before the charging starts to be performed, and the carriers trapped on the surface of the photoconductor drum remain as optical memory and appear as dark potential difference, thereby degrading the print quality.
On the other hand, there is known a configuration in which an electricity removing device is disposed between a transfer device, which transfers a toner image from the photoconductor drum, and a cleaning device. According to this configuration, the distance on the circumferential surface of the photoconductor drum from the position where the irradiated electricity removing light is received and the position where electricity is charged by the charging device becomes longer. This ensures the time required for eliminating the carriers trapped on the surface of the photoconductor drum, and makes it possible to increase the rotation speed of the photoconductor drum. On the other hand, there is a problem that the toner remaining on the surface of the photoconductor drum and the toner transferred onto the transfer material are scattered and adhere to the electricity removing device, thereby reducing the amount of the electricity removing light that is irradiated toward the photoconductor drum. In view of this, in a configuration where the electricity removing device is disposed on the upstream side of the cleaning device, a light guide member is provided to protect the electricity removing device from the scattered toner.